Discharge device



Filed Dec. 11, 1931 Patented Feb. 26, 1935 OFFICE DISCHARGE DEVICE Cornelis Bastiaan Los, Einahoven;

Netherlands,

assignor to N. V. Philips Gloeilampenfabrieken, Eindhoven, Netherlands Application December 11 In Germany J 1931, Serial No. 580,457 an uary 3, 1931 5 Claims. (01. 25 027.5)"

The invention relates. to discharge tubes for full wave or polyphase rectification, more par-, ticularly to tubes comprising a single anode and two or more cathodes.

' is well-known to rectifier the shape of screen with an opening in which the incandescible cathode is arranged. As, in the latter case,

5 for operating reasons, an opening has to be provided, there always exists the described is ly advantageous with hoods which constitute the cathodes.

In order that the invention may be clearly understood and readily carried into effect it will be grammatical embodiments of the invention and a diagram of connections. In said drawing:

Figure 1 represents a discharge tube in which the anode is arranged in the screen separating the cathodes.

Figure 2 represents a form of execution in which the screen itself constitutes the anode. ,Figure'S represents a glow-discharge rectifier to which the invention has been applied.

Figure 4. shows the circuit-arrangement of the rectifier described. p

In Figure 1, incandescible cathodes 4 and 5 are arranged on thepress 2 of the stem 3 of a discharge tube 1. the middle between the insulating or conductive material in which an, anode 7, for example of graphite, is arranged. If the screen 6 consists of insulating materiaLthe-anode h may be sealed-inat the top orat the bottom of the tubeand screen may be provided with a Wire. 4

separate supply In the form of execution represented the screen must e te substance 10 baked to the wire.

Figure 2 represents, by way of example, a. form merals as in Figure 1. The dischargetube has a symmetrical shape because there are two stems 11 and 12 each carrying an mcandescible cathode. Figure 3 represents a rectifier comprising cold a very small surface. The open ends of the glass tube are closed by hoods 13 and 14, for example of ferrochromium, which have a large surodes.

face so that they may act extremely well as cath- The hoods 13 and 14 are sealed on to the glassof the discharge tube 1 and provided with supply wires 15 and 16. On the inner side they may be provided with a coating adapted to emit electrons.

The discharge tube described may contain a gaseous filling consisting, for example, of the rare gases argon, helium, neon or crypton and having, if desired, added to it another gas such as mercury vapor. In the forms of execution shown in the Figures 1 and 2, a so-called Wehnelt cathode is utilized as the incandescible cathode. The screen ably has a small aperture through which equalization of pressure between the various portions of the discharge tube may take place. the screen is made of metal, the screen as a rule does not form along its whole circumference a perfect joint with the glass wall of the tube, so that in this caseno special opening is required for the equalization of the gas pressure between the chambers of the tube.

Figure 4 shows the circuit-arrangement of such a rectifier. The secondary winding of a transformer 1'? which may be connected at 18 to the alternating current network, has a centre tap leading to one of the terminals 19 of a directcurrent load the other terminal of which is connected to the anode '1 of the discharge tube. The incandescible cathodes 4 and 5 of the discharge tube are supplied from the secondary winding by means of tapped portions located near each end thereof. All the auxiliary devices such as resistances, switches, ammeters, etc. are omitted in this circuit-arrangement for the sake of clearness. During the one half-cycle the current flows through the upper part of the secondary winding, via thedirect-current terminals 19 and the direct-current load to the anode '1 and thence via the incandescible cathode 5 back to the upper part of the secondary winding of the transformer 17. During the second half-cycle of the alternating current the current flows through the lower part of the secondary winding via the direct-current terminals 19, the anode 1'1, the incandescible cathode 4 and back to the lower end of the secondary winding. The two halves of the alternating-current cycle: consequently pass in the same direction through the direct-current load connected at 19.

Although the forms of execution shown relate In case to rectifiers for full wave rectification of an alternating current, it is evident that with rectifiers for a threeor polyphase alternating current it is also possible, without departing. from the principle underlying the present invention, to obtain a complete screening between the incandescible cathodes.

What I claim is:

1. A gaseous discharge device, comprising a vitreous envelope, both ends of which are closed by metal hoods sealed to the said envelope and forming the cathodes of the device, and a partition disposed centrally between said cathodes, said partition fully separating said cathodes, and an anode forming a unitary structure with said partition.

2. A full wave rectifier tube comprising an envelope, a partition wall in said envelope, disposed centrally and dividing said tube into two completely separated chambers, a cathode for each of said chambers and forming part of the envelope, and a common anode forming part of said partition wall, said anode being adapted to be connected through a load to the midpoint of a transformer winding to the two ends of which may be connected the cathodes.

3. A gaseous discharge tube, comprising an envelope divided into a'plurality of chambers, a common partition structure completely separating said chambers, and a plurality of electrodes of one polarity, forming part of the wall of the envelope, one being provided for each of said chambers, and a common electrode of the other polarity forming part of said partition structure.

4. A full wave rectifier tube having an envelope, a gaseous filling therein, a central'partiticn dividing said envelope into two hermetically separated chambers, a common electrode forming part of said partition and having an active surface plementary electrodes, one for each chamber, said complementary electrodes forming wall portions of said envelope.

5. A full wave rectifier tube having an envelope, a gaseous filling therein, a partition dividing said envelope into two chambers, an anode carried by said partition and having an active surface in each of said chambers, and a cold cathode for each of said chambers, said cathodes forming metallic wall portions of said envelope.

CORNELIS- BASTIAAN LOS. 

